The present application relates to an organic electronic device, a method for production thereof, and a new organic semiconductor molecule.
A large variety of electronic devices rely on field effect transistors (FET) including thin film transistors (TFT). The FET consists of a channel-forming region and a source/drain region which are formed in a silicon semiconductor substrate or a silicon semiconductor layer, a gate insulating layer of SiO2 which is formed on the surface of a silicon semiconductor substrate or a silicon semiconductor layer, and a gate electrode opposite to the channel-forming region, with the gate insulating layer interposed. Alternatively, it consists of a gate electrode formed on a support, a gate insulating layer covering the support including the gate electrode, and a channel-forming region and a source/drain region which are formed on the gate insulating layer. FETs with such a structure need a very expensive semiconductor manufacturing system, and their production is being challenged for cost reduction.
Much attention is now focused on research and development of organic semiconductor devices including FETs based on organic semiconductor materials capable of production by spin coating, printing, or spraying, which do not need vacuum technology. Organic semiconductor materials reported so far are mostly p-type ones but scarcely n-type ones. Both n-type and p-type organic semiconductor materials should be developed side by side so that they are applied to p-n junction, optoelectric conversion element, bipolar transistors, complementary transistors, and other transistors (see Shinji, A., et al. J. Am. Chem, Soc. 2005, 127, 14996 hereinafter referred to as Non-Patent Document 1, Facchetti, A., et al. Angew. Chem. Int. Ed. 2003, 42, 3900 hereinafter referred to as Non-Patent Document 2, Locklin, A. J., et al. Chem. Mater. 2003, 15, 1404 hereinafter referred to as Non-Patent Document 3, and Chesterfield, R. J., et al. Adv. Mater. 2003, 15, 1278 hereinafter referred to as Non-Patent Document 4). Among coatable n-type organic semiconductor materials are pentacene substituted with fluoroalkyl groups (see Sakamoto, Y., et al. J. Am. Chem. Soc. 2004, 126, 8138 hereinafter referred to as Non-Patent Document 5), oligothiophene and thiazole oligomer (see Yoon, M. H., et al. J. Am. Chem. Soc. 2005, 127, 1348 hereinafter referred to as Non-Patent Document 6). Development of p-type organic semiconductor materials with improved characteristic properties is crucial.
For their application to various devices, the n-type organic semiconductor materials that appear in the documents listed above are synthesized by complex processes in several stages. However, development of simple processes is very important for economical production of organic electronic devices in practical use. The main disadvantage of n-type organic semiconductor materials is susceptibility to oxidation in air, which leads to their limited selections and necessitates complicated fabrication processes for their fabrication into organic electronic devices. Moreover, there is also a need for p-type organic semiconductor materials with improved characteristic properties.